Filtrate Eyewear Sink Sunglasses Injected memory flex (Grilamid TR-90) frame for economical and durable everyday "use n abuse" option High Def CR-39 resin polymer lens that is half the weight of glass with excellent optical clarity High resistance to scratch and 100% resistance to UV rays Polarized Lens eliminates 99% of glare from water, snow or other flat surfaces for enhanced visibility and color contrast Metal Hinges